Terminal for rail bonds



Dec. 29, 1942. E. J. SABOL 2,306,542

TERMINAL FQR RAIL BONDS Filed Sept. 25, 1940 Patented Dec. 29, 1942 uairan stares smear QFFICE Tasman son nan. some Ernest J. Sabol, Pittsburgh, Pa. Application September 25, 19st, semi No. 35am 3 Claims. (Cl. car-2M) This invention relates to terminals for rail bonds and is particularly'concerned with the problem of providing an easily installed terminal of the mechanically applied type for signal rail bonds, which is adapted for use in connection with the $4 inch deep, inch round holes formed in the sides 'of the heads of railroad rails for this purpose and which vary in size due to inaccurate drilling.

The accompanying drawing illustrates the principles of the invention:

Figure 1 showing a signal bond;

Figures '2 and 3 showing an element used with this bond in longitudinal section and top elevation, respectively;

Figure 4 showing in section the bond as it is installed;

Figure showing in section the use of the element shown by Figures 2 and 3; and

Figure 6 showing the same as Figure 4 but with the bond installed in an oversized rail hole.

More specifically, the drawing shows the combination of a rail bond terminal having a head I and a projecting pin 2 with a malleable bushing 3 for fitting the rail hole a and having a bore 5 for receiving the pin 2.

The terminal is used by inserting the bushing 3 into the hole 4. The bushing is made with an outside size and contour adapting it to fit acorrectly sized rail hole, variations in the size of the rail holes being always over rather than under. In case the rail hole is too big, such as is indicated by Figures 5 and 6, a punch 6 is placed on the outside end of the bushing and hit with a hammer, the punch having a mandrel i that fits in the bore 5 and maintains its contour during this operation. The longitudinal compression thus applied the bushing 3 causes its lateral expansion until it properly fits the hole. The result is an accurately sized hole for receiving the pin 2 of the terminal. Figure 4 shows the vbond installed in a correctly sized hole.

It has been found that by making the pin 2 and the bore 5 of the bushing 3, with a certain definite taper, relatively light hammer blowswill effect the installation of the terminal with extreme firmness. It has been found, as a matter of fact, that the easier the pin 2 can'be driven into the bore 5, the more firmly fixed it becomes. It is to be understood that as the tapered pin of the terminal is driven into the tapered bore of the bushing, expansion of the latter is effected, and since the bushing has been made to exactly slight expansion resulting from the use of very slight force, produces a very firm installation.

Aspreviously mentioned, the -standard size of the rail hole drilled in the side of a railroad head is of an inch in depth and of an inch in diameter. It follows that the outside size of the bushing 3 should be just sufilciently smaller than these dimensions to permit the bushing 3 being slid into the rail hole when it is the proper size. As previously indicated, the tapers of the pin 2 and of the bore 5 of the bushing 3, are impor- @238 of an inch in diameter in of an inch of length. The tolerances'of these tapers should not exceed .005 of an inch over or under if adequate holding power and easy installation are to be obtained. The extreme holding power and easy installation qualities imparted'the terminal by resorting -to the use of these specific tapers, could not be' obtained were it not for the fact that the use of the tool 6 in conjunction with the bushing 3 permits the maintenance of precision-fitting even though the various rail holes may differ in diameter.

The pin 2 is somewhat malleable and can be expanded at its .end when this hits the rail hole bottom, the bore in the bushing '3 at its smaller inside end being flared to receive the expanded pin end. This effect is shown by Figures 4 and 6.

I claim:

1. A method of installing a rail bond terminal having a projecting tapered pin in a rail hole, said method being characterized by the use 01' a continuous bushing having a tapered bore designed to receive said pin with a drive flt and made of malleable metal, the bushing being inserted in said hole and expanded to a tight fit fit the rail hole by the use of the punch 6, the

therein by longitudinal compression while maintaining the size and contour of its said bore by a mandrel inserted therein, said pin being then driven within said bore of said bushing, the pin and bushing being of substantially the same length.

2. A method of installing a rail bond terminal having a projecting tapered pin in a bottomed rail hole drilled in a side of the head of railroad rail, the said method being characterized by the use of a continuous bushing having a tapered bore designed to receive the said pin with a drive fit and made of malleable metal, the bushing having an outside contour to fit the said hole, the said bushing being expanded laterally by the said pin to flt the hole, the pin projecting through the bushing, the pin being then driven into the bushing and becoming upset to form a lock beneath the bushing when the terminal has been driven in the hole.

3. A method of installing a rail bond terminal having a projecting tapered pin in a bottomed rail hole drilled in a side of the head of a railroad rail, the said methodbeing characterized by the use of a'continuous bushing having a tapered bore designed to receive the said pin with a drive fit and made of malleable metal. the bushing having an outside contour to fltthe hole, inserting the bushing into the hole in the rail, placing the pin in the bore of the bushing and driving the pin through the bore of the bushing until it projects through the bore into engagement with the bottom of the hole, and continuing the drivingof the pin until its portion projecting through the bore becomes upset to form a lock beneath the bushing when the terminal has been completelyinstalied in the hole.

ERNEST J. SABOL. 

